An egg white substitute material can be used in a wide variety of nutritional materials and in confectionaries like meringues. In selecting egg white substitute materials, two main factors have to be taken into consideration, namely whether or not the egg white substitute material has nutritional value and the degree of whipping or emulsifying ability exhibited by the substitute material.
Thus, a protein derivative, which is an enzyme hydrolyzed acid precipitated soy isolate, is described in "Functionality and Protein Structure," ACS Symposium 92, 1979, pages 125 to 146 (J. Adler-Nissen and H. Sejr Olsen, "The Influence of Peptide Chain Length on Taste and Functional Properties of Enzymatically Modified Soy Protein"), from which it appears that a series of hydrolyzates of acid precipitated soy protein have been prepared using different enzymes and different DH-values (DH is an abbreviation for degree of hydrolysis, defined hereinafter), from which it was discovered that both the whipping and emulsifying properties of these soy protein hydrolyzates had an optimum in a certain DH interval. The whipping and emulsifying ability of these soy protein hydrolyzates is good, but open to improvement.
Also, soy protein derivatives with excellent whipping properties are known, but they do not have a sufficiently high nutritional value, and may even be bitter, which characteristic limits their application in food formulations. See, for example, J. Am. Oil Chemists' Soc., March 1979, Vol. 56, pages 345 to 349.
Thus, a need exists for an egg white substitute material based on soy protein, which exhibits excellent whipping or emulsifying ability and good nutritional value combined with the absence of bitterness.